S. Engin Kilic

A computer-aided graphical technique for the optimization of machining conditions

Abstract A computer-aided graphical technique that is capable of mapping all of the relevant constraints and a number of objective function contours in the cutting-speed vs. feed-rate plane is described. The software developed first generates all data points necessary to draw the constraints and the contours and then loads the data to a graphics package, which draws and displays the contours together with the constraints on the same graph. All of the graphical points are obtained analytically, hence a sufficient number of data points can be generated to draw the contours accurately and quickly. Redundant feed-rate constraints can automatically be eliminated from display if desired. The optimum point can readily be identified by inspecting the graph displayed on the monitor screen. The parameters that are assumed to be most effective in determining the optimum point can easily be changed and the revised graph can be inspected for possible improvements in the optimum value. Hence, the technique is also suitable for a sensitivity analysis. Results of some test runs are presented to explain the implementation of the technique.

Dissimilarity maximization method for real-time routing of parts in random flexible manufacturing systems

This paper presents a dissimilarity maximization method (DMM) for real-time routing selection and compares it via simulation with typical priority rules commonly used in scheduling and control of flexible manufacturing systems (FMSs). DMM aims to reduce the congestion in the system by selecting a routing for each part among its alternative routings such that the overall dissimilarity among the selected routings is maximized. In order to evaluate the performance of DMM, a random FMS, where the product mix is not known prior to production and off-line scheduling is not possible, is selected for the simulation study. A software environment that consists of a computer simulation model, which mimics a physical system, a C++ module, and a linear program solver is used to implement the DMM concept. In addition to DMM, the simulation study uses two priority rules for routing (i.e., machine) selection and seven priority rules for selecting parts awaiting service at machine buffers. The results show (1) DMM outperforms the other two routing selection rules on production rate regardless of the part selection rule used, and (2) its performance is highly dependent on the part selection rules it is combined with.

Design of a Multi Agent Based Virtual Enterprise Framework for Sustainable Production

In this paper a Platform as a Service (PaaS) based multi agent virtual enterprise framework for sustainability is introduced which is designed in order to facilitate the collaboration between Small and Medium Sized Enterprises (SMEs) working in Aviation and Defense Cluster of OSTIM Organized Industrial Region in Ankara, Turkey. In order to enable SMEs to capture opportunities and design products collaboratively in a network, a Virtual Enterprise framework shall be developed. This framework also targets to improve sustainability for the SMEs in the breeding environment and prepare them for the forthcoming legislation regarding reduction of environmental impact, energy management and minimizing carbon emissions.

A Model for Predicting Theoretical Process Energy Consumption of Rotational Parts Using STEP AP224 Features

Energy efficiency in manufacturing has become a key concern due to the increased awareness of the adverse effects of global warming. First step for increasing energy efficiency is to quantify the energy consumed for manufacturing processes. This study presents a prediction model for the theoretical energy that is consumed during the manufacturing processes of a rotational part and resulting CO2 release. Theoretical energy is the tool tip energy required to remove the given volume of chip. Prediction model is based on the volume removed for each STEP AP224 feature and the specific cutting energy for the given material.

An Eco-Improvement Methodology for Reduction of Product Embodied Energy in Discrete Manufacturing

There is an increasing awareness of global warming due to excessive greenhouse gas emissions and need to decrease the adverse effects of production on environment. It is known that greenhouse gasses are mainly originated from the fossil fuel combustion for electrical energy generation. This paper proposes an eco-improvement methodology for minimizing the product embodied energy by decreasing the electrical energy dependence of production. The methodology involves generation of STEP based process plan resulting in minimum embodied energy and simulation models enabling what-if analyses. The proposed eco-improvement methodology will be implemented in refrigerator compressor plant of Arcelik A.Ş., aiming at assessment and reduction of energy consumption in discrete manufacturing.